With the exception of the base of the cabinet, this set is in
excellent condition. The 183X was first advertised in September, 1939. It used the 14AP4 "Teletron" CRT, which has an "intensifier" anode that produced a brighter picture than the earlier tubes used by DuMont.

The X series receivers also have a switch that selects two sets of scan rate controls. When the set was first introduced, the dual controls were apparently used to select between 441 line transmissions from NBC and CBS, and a proposed higher scan rate proposed by DuMont. In 1941 the FCC approved a 525 line standard, and DuMont then suggested that the receiver could be used to watch experimental field sequential color broadcasts:

Froim Rider Volume 13

In 1941 RCA and CBS were both broadcasting experimental field sequential color, using various frame rates. Here is a summary from Ed Reitan's site:

February 20, 1941

Color television pictures in motion were put on the air by NBC in its first telecast of color by mechanical means from a TV studio.

From DuMont Receiver Manual for its multi-standard *Model 180X to 183X* set:

375 line, 120 field system announced (ref. IRE April 1942 paper, also see Sept. 1943 paper).

From DuMont Receiver Manual for its multi-standard *Model 180X to 183X* set:

(a) CBS Color pictures use 375 lines per frame at 60 frames per second
which requires a horizontal scanning rate of 22,500 lines per second,
and a vertical scanning rate of 120 field scans per second.

The other surviving 183Xs have the switch located on the front panel, as described in the Rider maual (above). The switch on our set is located on the rear panel, and is marked "B/W" and "Col". It is likely that our set was used in 1941 for viewing experimental color broadcasts (in black and white, of course).

After the war, our set was used in Washington, DC, to receive
W3XWT. This card was taped inside the back of the set:

W3XWT started broadcasting in 1945, but, since no sets were
manufactured during the war, this pre-1945 set was used in Washington.
Here is an article about W3XWT.

From the 1944 movie "Brewster's Millions". A DuMont 183 has been made to
look more modern by the art department. The image on the screen is
pasted on.